Blueschist

Tuff

Blueschist and Tuff

Blueschist

Tuff

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Definition

Blueschist is a metamorphic rock which is generally blue in color and is formed under conditions of high pressure and low temperature

Tuff is a type of rock made of volcanic ash ejected from a vent during a volcanic eruption

History

Origin

USA

Italy

Discoverer

Edgar Bailey

Unknown

Etymology

From French schiste, Greek skhistos i.e. split

From a Latin word tophous then in Italian tufo and finally tuff

Class

Metamorphic Rocks

Igneous Rocks

Sub-Class

Durable Rock, Medium Hardness Rock

Family

Group

Volcanic

Other Categories

Fine Grained Rock, Medium Grained Rock, Opaque Rock

Fine Grained Rock, Opaque Rock

Texture

Foliated

Clastic, Pyroclastic

Color

Blue, Bluish - Grey, Purple, Shades of Blue

Brown, Grey, Yellow

Maintenance

Less

Durability

Durable

Water Resistant

✔ ✘

Scratch Resistant

✔ ✘

Stain Resistant

✔ ✘

Wind Resistant

✔ ✘

Acid Resistant

✔ ✘

Appearance

Dull and Banded

Dull, Vesicular and Foilated

Uses

Architecture

Interior Uses

Floor Tiles, Flooring, Homes, Hotels, Kitchens

Decorative Aggregates, Entryways, Flooring, Homes, Interior Decoration

Exterior Uses

Garden Decoration, Office Buildings

As Building Stone, As Facing Stone, Garden Decoration, Office Buildings, Paving Stone

Other Architectural Uses

Curbing

Industry

Construction Industry

As Dimension Stone, Cobblestones, Rail Track Ballast, Roadstone

Building houses or walls, Construction Aggregate

Medical Industry

Antiquity Uses

Artifacts, Monuments, Sculpture

Artifacts, Monuments, Sculpture, Small Figurines

Other Uses

Commercial Uses

Cemetery Markers, Commemorative Tablets, Creating Artwork, Curling, Tombstones

Creating Artwork

Types

Metamorphic rock

Welded tuff, Rhyolitic tuff, Basaltic tuff, Trachyte tuff, Andesitic tuff and Ignimbrite.

Features

Has High structural resistance against erosion and climate, Very fine grained rock

Always found as volcanic pipes over deep continental crust

Archaeological Significance

Monuments

Famous Monuments

Easter Island in the Polynesian Triangle, Pacific Ocean

Sculpture

Famous Sculptures

Pictographs

Petroglyphs

Figurines

Fossils

Absent

Formation

Blueschist forms due to the metamorphism of basalt and other rocks with similar composition at high pressures and low temperatures and approximately corresponding to a depth of 15 to 30 kilometers and 200 to 500 °C.

Tuff is formed when large masses of ash and sand which are mixed with hot gases are ejected by a volcano and avalanche rapidly down its slopes.

Composition

Mineral Content

Albite, Chlorite, Epidote, Garnet, Glaucophane, Lawsonite, Muscovite or Illite, Quartz

Calcite, Chlorite

Compound Content

Aluminium Oxide, CaO, Iron(III) Oxide, FeO, Potassium Oxide, MgO, MnO, Sodium Oxide, Phosphorus Pentoxide, Silicon Dioxide, Titanium Dioxide

Hydrogen Sulfide, Sulfur Dioxide

Transformation

Metamorphism

✔ ✘

Types of Metamorphism

Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism, Hydrothermal Metamorphism, Impact Metamorphism, Regional Metamorphism

Weathering

✔ ✘

Types of Weathering

Mechanical Weathering

Biological Weathering, Chemical Weathering, Mechanical Weathering

Erosion

✔ ✘

Types of Erosion

Chemical Erosion, Coastal Erosion, Water Erosion, Wind Erosion

Chemical Erosion, Coastal Erosion, Glacier Erosion, Sea Erosion, Water Erosion, Wind Erosion

Properties

Physical Properties

Hardness

3.5-44-6

1 7

👆🏻

Grain Size

Fine to Medium Grained

Fine Grained

Fracture

Conchoidal

Uneven

Streak

White to Grey

White

Porosity

Highly Porous

Luster

Dull

Vitreous to Dull

Compressive Strength

220.00 N/mm²243.80 N/mm²

0.15 450

👆🏻

Cleavage

Slaty

Toughness

1.5

Specific Gravity

3-3.22.73

0 8.4

👆🏻

Transparency

Opaque

Density

2.8-2.9 g/cm³1-1.8 g/cm³

0 1400

👆🏻

Thermal Properties

Specific Heat Capacity

0.84 kJ/Kg K0.20 kJ/Kg K

0.14 3.2

👆🏻

Resistance

Impact Resistant, Pressure Resistant

Heat Resistant, Impact Resistant, Pressure Resistant, Wear Resistant

Reserves

Deposits in Eastern Continents

Asia

Japan, Turkey

Afghanistan, Armenia, Azerbaijan, Burma, Cambodia, China, India, Indonesia, Iran, Japan, Malaysia, Mongolia, Nepal, North Korea, Pakistan, Saudi Arabia, Syria, Taiwan, Thailand, Turkey, Vietnam, Yemen

Africa

Egypt, Ethiopia, South Africa

Cameroon, Cape Verde, Eritrea, Ethiopia, Kenya, Libya, Madagascar, Nigeria, Rwanda, South Africa, Sudan, Uganda

Europe

France, Greece, Iceland

France, Georgia, Germany, Greece, Iceland, Italy, Netherlands, Poland, Portugal, Spain, United Kingdom

Others

Antarctica, Hawaii Islands

Deposits in Western Continents

North America

USA

Canada, Costa Rica, Panama, USA

South America

Argentina, Bolivia, Brazil, Chile, Ecuador, Paraguay

Deposits in Oceania Continent

Australia

New Zealand

Central Australia, Western Australia

All about Blueschist and Tuff Properties

Know all about Blueschist and Tuff properties here. All properties of rocks are important as they define the type of rock and its application. Blueschist belongs to Metamorphic Rocks while Tuff belongs to Igneous Rocks.Texture of Blueschist is Foliated whereas that of Tuff is Clastic, Pyroclastic. Blueschist appears Dull and Banded and Tuff appears Dull, Vesicular and Foilated. The luster of Blueschist is dull while that of Tuff is vitreous to dull. Blueschist is available in blue, bluish - grey, purple, shades of blue colors whereas Tuff is available in brown, grey, yellow colors. The commercial uses of Blueschist and Tuff are cemetery markers, commemorative tablets, creating artwork, curling, tombstones.